The purpose of this grant application is for Baylor College of Medicine/Texas Children's Hospital (TCH) Heart Center to become a Clinical Center of the Pediatric Heart Network sponsored by NHLBI. The goal of the PHN is to evaluate therapeutic and management strategies for children and adults with congenital heart defects and for children with inflammatory heart disease, heart muscle disease, and arrhythmias through multicenter clinical research. Baylor/TCH Heart Center has experienced multidisciplinary leadership in Cardiology, Cardiac Surgery, Cardiac Critical Care, and Cardiovascular Anesthesiology. TCH has a large patient population with diverse diagnoses undergoing over 550 open heart cases, 1000 cardiac catheterizations, 17,000 echocardiograms, and encountering more than 80 new infants with single ventricle anatomy annually. With these qualifications, Baylor/TCH Heart Center proposes to become a major contributing Clinical Center of the PHN. The clinical research protocol for this application compares regional cerebral perfusion (RCP) vs. deep hypothermic circulatory arrest (DHCA). During neonatal aortic arch reconstruction, RCP duplicates conditions achieved with DHCA, a procedure that has been associated with adverse acute and long term neurological outcomes. RCP has been widely adopted in the past decade without extensive supporting data, either in experimental animal models, or human outcomes. There is only one small single center prospective randomized controlled trial of RCP vs. DHCA, finding no difference in neurodevelopmental outcome at 1 year. The Single Ventricle Reconstruction Trial, in the same patient population, was not designed to collect neurological data or assess long term neurodevelopmental outcome. We are proposing a multicenter, prospective, randomized, controlled trial which is adequately powered, to compare early and longer term neurodevelopmental outcomes with RCP vs. DHCA. Our hypothesis is that RCP will lead to improved neurodevelopmental outcomes vs. DHCA. RELEVANCE: This large multicentered study is designed to determine the preferred method of cardiopulmonary bypass for neonatal aortic arch reconstruction. If as hypothesized, regional cerebral perfusion results in a better neurodevelopmental outcome at 18-22 months, this is expected to change practice, and improve lifelong health status for a significant portion of the approximately 9000 infants who undergo cardiac surgery in the first year of life annually in the United States.